


High Tides

by guilty_pleasures_abound



Category: Gravity Falls
Genre: F/M, Flirting, Human/Monster Romance, Mermaids, POV Female Character, POV Second Person, Post-Canon, Post-Weirdmageddon, Sea Grunkles, Stan O' War II, Unsafe Sex, Vaginal Fingering, Vaginal Sex
Language: English
Status: Completed
Published: 2019-05-04
Updated: 2019-05-04
Packaged: 2020-02-18 14:13:44
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 9,753
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18701239
Author URL: https://archiveofourown.org/users/guilty_pleasures_abound/pseuds/guilty_pleasures_abound
Summary: The sound of the engine dimmed, idling in the water, and you opened your eyes to find it almost directly above you, the blurry outline of Stanley Pines leaning over the side of the deck.Now or never.[Female, non-human reader]





	1. Chapter 1

**Author's Note:**

> Can I pretend that this took so long to write because I was waiting for Mer-May? Of course I can!!
> 
> Deepest thanks to my followers on [tumblr](https://guilty-pleasures-abound.tumblr.com), who have been cheerleading and waiting for this fic with enthusiasm. Y'all are the best.
> 
> Extra thanks to sil-ky/Silouxa, for their [absolutely adorable, outstandingly cute Stan/Mermaid art that most definitely inspired this fic.](https://sil-ky.tumblr.com/post/184013749693/this-was-rrreally-fun-to-draw) And because I'm me, I of course made it smutty. Hope you like it, friend!
> 
> Finally, cheers to [nschimm](https://archiveofourown.org/users/nschimm/pseuds/nschimm) for giving this a once over for me. They are also writing a mermaid piece, by the way, so keep an eye out.
> 
> (Pst. If you want to skip straight to the porn, I won't judge you. It's chapter two.)

Word traveled surprisingly fast in the ocean. Even faster when it was a royal decree from Prince Mermando.

Stanley and Stanford Pines. The beloved uncles of his dear friend Mabel, the human girl who had helped the trapped prince return to his people. They were traveling by sea on a boat named the Stan O'War II, and they were to be protected.

Needless to say, royal protection of two human men was quite the gossip, and immediately piqued your interest. If they were half as interesting as the niece that Mermando spoke so highly about, they were sure to be worth finding.

They did not disappoint. The tales and rumors surrounding the Stan O’War II were quick to spread, and for the most part, surprisingly complimentary.

“They stopped a seal hunt,” the selkies whispered with reverence. “They knew us by sight, and came to our aid!”

“They sought our knowledge,” gossiped the Oceanids. “The six-fingered one was clever, he bested our riddles.”

“They subdued a Tlanusi!”

“They evaded the Yacu-mama!”

“They outsmarted Tamatoa!”

The closer you got to finding them, the more interesting the rumors; until finally, you found yourself staring at the infamous ship itself.

They had made quite a tour of the world's oceans, their journey seeming to have started in arctic waters, but had gradually drifted south, closer and closer to the equator until you caught up with them on their way to the Galapagos Islands.

And yet—looking at the belly of their boat, their water-distorted figures up above—you found yourself... shy. You had never interacted with a human before, your kind tended to stay out of their way whenever possible. It typically did not end well, when humans and merfolk met. And despite the blessing these men had received from Prince Mermando, along with the tales of their friendly interactions with others of your ilk, you just couldn't get past your nerves.

You considered; these men were decreed protected. Well. You could do that. You had come this far, traveled this long, the least you could do was look after them.

They were certainly interesting fellows, you could say that. You liked to listen to them chat at night; it was easier to hide under the shadow of the hull with the cover of darkness to aid you, listening to their deep voices.

Sometimes they spoke of their journey, of the creatures and beings they had encountered. Sometimes they spoke of their family—you got to hear more of the famous Mabel, along with her brother Dipper, and a couple others called Soos and Wendy, who did not seem blood related but where treasured as such. Those conversations were usually happy, joyful; sadly unlike the conversations about their parents, or even about themselves, which tended to be sad and remorseful. You were fascinated, to say the least.

So when you finally encountered one of them face to face, you were disappointed that it was under stressful circumstances.

The storm had been raging for the better part of the evening, the driving rain and heavy winds fighting them from above, and the turbulent toss and turn of the water fighting from below. It was so rough even you had to dive deeper to keep from being thrown around. It put the Stan O'War out of your sight, the water too dark and unsteady to keep track of them, filling you with anxiety. You'd been following in their wake for too long to lose them now!

As it turned out, it wouldn't be a problem, as the sound of something heavy hitting the surface drew you up from the safety of the deeper water.

He was struggling, limbs thrashing against the swirl of the ocean, a wave pushing him below the surface. You couldn't tell just yet which of the brothers it was, the light from their boat barely visible through the foam, but you knew that if you did not act, he would be sure to drown. You were not about to let that happen.

Jaw clenched with determination, you swam hard against the turbulent water, reaching the flailing man just as his limbs were starting to slow, exhaustion and lack of air beginning to take its toll.

“I've got you,” you murmured, hooking your arms under his from behind, swimming as hard as you could with his heavy weight toward the surface.

He gasped as soon as you hit air, coughing and hacking as you searched frantically for their boat.

“STANLEY!” you heard a familiar voice bellow, jerking your attention off to your left, where the Stan O’War II was bobbing and teetering, Ford’s outline on deck just barely visible in the torrential downpour.

Immediately you started swimming toward him, pulling Stan along with you and being careful to keep his head above the water, the man still gasping and coughing and trying to get his breath back.

“What the hell?” he finally gasped, trying to twist in your grip, attempting to crane his neck back to look at you, but you just kept holding tight; swimming as hard and as fast as you could toward his vessel.

“STANLEY!” you both heard Ford shout again, and this time Stan managed to call his name back in answer.

A moment later and you were right beside the boat, twisting around so Stan could reach up to Ford’s waiting hand, the two of you working in tandem to get Stan back on board.

“Are you alright?!” Ford asked his brother frantically, a crack of lightning across the sky illuminating the terrified worry on his face for a brief moment. A moment after that, Stan was out of your hands and completely returned to the deck of his boat.

“I’m fine!” you heard him say, his voice somehow even scratchier than usual from his coughing. “Sixer, I’m good!”

Then a silhouette—barely backlit from their struggling deck lights—looking back over the side of the boat, and you gasped before ducking back under the surface. They wouldn’t be able to see you, even if you stayed close, you felt sure; between the waves and the darkness your presence would be hidden from their sight.

“Something helped me,” you heard Stan say. “Something pulled me up and brought me back to the boat.”

“What?! What was it?”

“I don’t know, I couldn’t see.”

“Are you sure—?”

“Sixer, I was about thirty seconds away from drowning when they grabbed me. I’m sure.”

A violent wave made them both shout and you nearly bashed your nose against the hull; it was time to retreat back to deeper water, to ride it out until the storm had passed. You’d keep an ear out for any more trouble, of course, but you hoped they would come out of the storm without further peril.

Thankfully, the storm hadn’t damaged them too much, and the Pines men were able to limp along the rest of the way to the Galapagos Islands. You trailed along behind them until they got within range of the main island, clearly heading there to dock and get supplies, manage any repairs to their vessel, and probably talk to the locals. It was a little too populated for your tastes, so you dropped back to wait for them to depart for less busy waters.

***

There were rumors of harpies, which was what brought them to the islands, but after three days of searching you could tell Stan was getting bored.

“I’m going fishing,” you heard him declare to Ford on day four, “just radio me if you find anything, alright?”

“Stanley, do you really think sitting on the boat with a fishing rod will actually be more interesting than exploring the islands?”

“At least it’ll be more productive, since I’ll end up with dinner. Come on, Sixer, there’s only so long I can watch you take notes and draw.”

You grinned a little at the exasperated sigh Ford gave, lingering under their boat to listen to their conversation. You were kind of on Stan’s side with this one, simply for your own benefit; when they took to land, you were left unable to follow their adventures, only able to hear them talk about it after the fact. Human fishing might not be terribly exciting, but perhaps Stan would put on some music to entertain you both.

“Stay nearby,” Ford finally grumbled, “if I find the harpies I might need your help in a hurry.”

“Yeah yeah, aye aye,” Stan acknowledged, the two brothers parting ways for the day.

He did in fact put music on, something upbeat and cheerful, and you heard him humming and singing along as he got his fishing gear and sent the line into the water to wait for a bite. He was terrible, his scratchy voice not matching the notes of the singer’s at all, but his enthusiasm amused you.

Then the sound of rhythmic thumping, and you just had to see what on earth he was up to.

You risked a peak above the surface—far enough away, you hoped, to go unnoticed—to find him dancing on the deck of the ship, carrying a life jacket in his hands as if it were a dance partner. You couldn’t help but laugh, tucking the sound under the water line to hide it, watching him sway and step around the deck with surprising grace.

They were so handsome, these men. Strong jaws, wide shoulders, big hands. You even liked the grey of their hair, and you liked how it grew all over their bodies as well as their heads and faces.

You were almost tempted to applaud him when he did a dramatic dip to the life jacket as the song ended, laughing to himself as he straightened a moment later.

Then he looked up and out at the ocean, and your eyes met.

“Wait!” you heard him shout as you ducked back down in a panic, sinking a few meters below the surface with your hearts racing.

Why?! _Why_ was the idea of talking to them so nerve-wracking? They hadn’t once indicated any sort of interest in hurting your kind, and in fact you were fairly sure that Ford would delight in talking to and examining you.

You groaned to yourself, covering your face with both hands as you sank further down, traveling the last few meters to the rocky bottom to lay on your back with embarrassment.

Then the sound of the Stan O’War’s engine coming to life, and you just knew Stan was heading this way. You had a choice to make; keep running away, or let him catch up.

The clock was ticking for you to make your decision, the engine becoming louder and louder as it drew close. After a moment of intense internal battle, you pulled your hands away from your face to pound on the rocky bottom on either side of you with determination.

“Orca up!” you scolded yourself. “He’s just a man!”

The sound of the engine dimmed, idling in the water, and you opened your eyes to find it almost directly above you, the blurry outline of Stanley Pines leaning over the side of the deck.

Now or never.

A deep breath, water fanning through your gills, before you moved up from the ocean floor toward the surface.

You knew Stan saw your approach by the way he leaned back, still staring down at the water but not quite so far over the railing. Then the top of your head was above the surface, your eyes looking shyly up at his as your mouth stayed below to water line to hide the nervous bite of your lip.

“Holy shit,” he said, staring at you with wide eyes. “I told Sixer I wasn’t imagining things. You’re the one who saved me when I fell overboard, aren’t you?”

You nodded, and his mouth suddenly spread into a wide grin as he folded his arms down onto the railing, putting his weight on his elbows to lean closer to you. “Ha! I knew it! Take that, Poindexter!”

That last remark he aimed back toward the island Ford was exploring, and you couldn’t help but grin at the good-natured jab he was taking at his brother’s expense, even if the other twin couldn’t hear him.

“I’m Stan,” he said next, looking back down at you with that grin still firmly in place. “What’s your name?”

You rose your head up a little higher to answer him, and he echoed you, trying out the sound of your name in his mouth.

“That’s pretty,” he said, your blush returning to your face at the compliment.

“Thank you,” you replied in a murmur.

“So… uh, why exactly have you been following us?” He raised an eyebrow at you.

You tried to school your face into the definition of innocence. “Who says I’ve been following you?”

He gave a gruff laugh, shifting his weight slightly. “Because you’ve been pinging on the sonar for weeks, we just couldn’t figure out what you were.”

Busted. You ducked back below the water with a flustered groan, but you could hear Stan calling after you, “No, wait! Come back!”

You slid back up to the surface bashfully, tucking a little closer to the side of the boat to hide your face against it, palms pressed against the slick metal.

“I’m not leaving,” you assured him. “I’m just… I didn’t know you knew I was here.”

“Yeah, well… Ford’s not good for much, but he’s got some swanky gadgets.” You could tell he was trying for leavity, and you risked a glance up at him to find him smiling gently at you. “Can't say I mind, honey. You saved my life. Thank you for that, by the way.”

You didn’t know what honey was, but you sensed from the way he used the word that it was a term of endearment, which sent your insides into all kinds of a flutter.

“You’re welcome,” you replied. “That’s… why I’m following you. To help you, when I can.”

“Really?” he sounded genuinely surprised, both eyebrows shooting up. “Why’s that?”

“Because I’ve heard many things about you, Stanley Pines. You and your brother have made quite a name for yourselves.”

That seemed to please him, his face lighting up and chest puffing out with pride. “Yeah? What’ve you heard?”

“You know, you should probably focus more on your actual fishing line rather than fishing for compliments,” you found the boldness to say, successfully distracting Stan’s gaze to where his fishing rod was secured to the railing. It was just long enough for you to duck under the boat, using the vessel itself to hide.

“Hey!” you heard him cry with indignation from above you, sure that he was leaning over the railing to scan the water.

You, meanwhile, bit your lip as you stayed under the cover of the boat, trying to calm your excitedly racing hearts. You didn't know why it made you so flustered, talking to him, it just _did_. You needed a breather.

You gazed out beyond the boat, spying the fishing lure you had nudged Stan into looking at several meters out. Maybe he'd forgive your sudden disappearance if you helped him catch some fish.

You took off with renewed determination, intent on doing just that.

In rich waters like these, it was thankfully fairly easy to do, your quick reflexes and refined hunting skills helping you snare a fish in no time, attaching it to Stan's fishing hook and giving it a quick tug. You smiled as the line jerked, the old sailor aptly reeling it in. You did that thrice more for good measure, finally plucking up the courage to come near the boat again as Stan wrestled the last fish on board.

“Was this you?” he chortled, holding up the most recent fish caught on the line; the others, you guessed, in some sort of bucket on deck.

You nodded, drifting a little closer to the boat as Stanley laughed, unhooking the fish and tossing it to his feet. It made a splash and a clunk that told you your bucket theory was correct.

“Don't tell Ford you helped me,” he grinned. “Make the know-it-all think I've become some kind of fishing wizard.”

You couldn't help but laugh, Stan's smile widening in return, looking a bit proud of himself. “You _are_ going to stick around until Ford gets back... aren't you?”

Ford wouldn't return for hours yet, unless Stan planned on summoning him back to the boat early?

“I'm always around,” you hedged, watching him sit on one of the chairs on deck and lean against the railing of the boat again.

“Are you scared of us?”

You had not expected him to ask that, and you felt color rise to your face. You hid it under the water line, pushing yourself to move a little closer to the boat.

“No...” you raised your mouth out of the water to mumble, and he raised a skeptical eyebrow.

“You sure?”

“Should I be?”

The corner of his lips tugged up a tiny bit. “Only if you plan on hurting us. Since you kept me from drowning I'm going to guess you don't.”

His statement was an amusing mix of a brag and a threat; the only thing that would have made it more obvious was if he had flexed his muscles. You didn't take it personally; it was only logical that he would be cautious.

“I told you,” you reassured him, “I'm here to help.”

“In exchange for...?”

You frowned, staring at him blankly for a moment.

“No one does anything for free, kid.”

You considered his assertion. It was a bit of a cynical one, in your opinion, but you could admit there was a grain of truth in there somewhere.

“I suppose...” you mumbled, folding your arms thoughtfully, “that I'm doing it for the sake of curiosity.”

“Curiosity?”

“I've never interacted with humans before. And what I've heard about you... well. I wanted to see.”

“You gonna tell me what you've heard about us this time, or you gonna disappear again?”

You ducked just under the surface coyly, looking up at his water-distorted face with a little smile.

“Oh come on! The suspense is killing me! We have a reputation among mermaids, how do expect me not to want to know?”

You came back up with a snicker, biting your lip as you considered what to tell him.

“You have our respect,” you finally said. “Your exploits have painted you to be brave, but merciful men.”

“Brave but merciful, huh?”

“Yes. You saved some of our selkie cousins from slaughter, did you not?”

Stan's chest seemed to puff up a bit with pride. “Well... yeah. We did.”

“And you treated our Oceanid cousins with respect, exchanging your knowledge instead of threatening or hurting them, like so many before you?”

Stan's prideful puff seemed to deflate a bit. You spread your hands with a little shrug. “Brave but merciful.”

“No wonder you avoid humans,” he murmured, “if ‘doesn’t try to kill us’ is your baseline.”

It was the truth, if a depressing one. You sank under the surface again, still looking at his face through the ripple of the water, his frown distinct even through the light distortion.

His face suddenly turning to the side—his attention jerked away to something behind him—brought you back up, the crackle of the ship’s radio coming through the cabin’s open door becoming clear once you broke the top of the water.

“Stanley! Stan, come in! Sixer calling Stan O’War, over!”

Stan disappeared from where he was leaning on the ship’s railing, presumably to answer the radio call. You stayed to listen curiously.

“Stan O’War to Sixer. You alright? Over.”

“No. I found the harpies, and they are _not_ keen to talk. I need backup to get out of here. Over.”

“Shit,” Stan murmured, then addressed his brother. “On my way. I’ll bring the sonic gun. Out.”

The start of the engine, and you backed away from the Stan O’War, looking anxiously toward the shore, worried what trouble was befalling the other Pines twin.

“I have to help Ford.” Stan was back at the railing, speaking to you, and you nodded in acknowledgement as you looked up at him.

“Be careful,” you bid him, receiving a nod in return.

***

It took them a lot longer to return than you would have liked. Thankfully, though they seemed a little worse for the wear, they also appeared to still be in one piece, alleviating your worries considerably.

You watched them return to their boat from a safe distance, wanting the two of them to concentrate on tending to themselves rather than being distracted by your presence. Satisfied that they were taking care of themselves and safe from harm, you set out to catch your own dinner for the evening.

It gave you time to think of your first true interaction with Stan earlier in the day. You hadn’t anticipated getting caught in such a way, but there was also a sense of relief; the ice was broken now, you had permission to approach them. More than that, Stan seemed to want you to; he had asked if you were going to stay to meet Ford, had seemed upset when he thought you were disappearing.

You also, to your embarrassment, couldn’t stop thinking of just how charming you found him. The stories you had heard hadn’t mentioned that; it wasn’t until you started listening in on their conversations at night had you come to that conclusion, fueled even more now by your too-brief interaction.

You liked it when he smiled. You liked the mischief in his eyes when he was being cheeky or boastful, you liked the rough sound of his laugh and his voice.

You liked Ford’s voice too, if you were being honest. They were so wildly different; Stan’s voice so scratchy and coarse, where Ford’s was deep and smooth. Equally appealing, somehow, despite their differences.

Voices that were strangely absent when you popped your head up beside their vessel later that evening. The sun had just set, the stars and moon bright overhead, which was usually when they would eat and talk, their voices easily floating up from the ship's galley.

Tonight was unusually quiet, which concerned you. Were they okay?

You were debating calling out for Stan when you heard heavy footfalls coming up to the deck. Out of habit, you ducked just under the surface, waiting to see who would appear.

It was Stan, looking tired, his broad hands resting on the railing as he looked out onto the water.

"I thought we were past this, kid," he said. "Why are you hiding?"

You sheepishly rose up, Stan's gaze shifting to you in the dim light from the stars.

"Sorry," you murmured. "Habit."

He gave a soft chuckle, rubbing the back of his neck with a long sigh. "Yeah. I get it."

"You and Ford okay?" you asked.

"Yeah, we're alright. Bit bruised but nothing serious. Ford's konked out already. Give the guy one advil and he's dead to the world."

He chuffed with amusement, and you nodded, thought you weren't quite sure what an "advil" was. A food that induced sleep, maybe?

"Anyway..." he mumbled. "Glad you're still around."

"I told you I would be."

"Yeah, I know, but I thought maybe I spooked you earlier or... something."

"Not yet," you said, swimming slightly closer. "Unless you brother tries to dissect me."

Stan chuckled, rubbing the back of his neck again. "No, no. Scan you with one of his gadgets and poke you a bit, maybe, but nothing painful."

"I'll hold you to that."

His smile was amused, but you could tell he was exhausted.

"Go to sleep, Stanley Pines," you encouraged him. "I'll be here tomorrow."

"Heh," he chuckled. "That obvious, huh?"

"You had a confrontation with harpies today. From what I hear, that's not always pleasant."

"I'll say."

"Tell me about it tomorrow?"

"You got it."

***

"Fascinating," Ford murmured under his breath, his hands spreading your tail fin for examination.

The six-fingered Pines had, in fact, been quite excited to meet you. He'd launched into a multitude of questions about your culture, where in the ocean you lived, what you ate. Anything he could think of that might be useful to his research.

"Gosh, forgive me if this is impertinent," he eventually said, scribbling frantically in his journal, "but may I examine you? Nothing horrifically invasive, I assure you, but I am deeply curious about your anatomy as a humanoid being."

You and Stan exchanged a knowing look, his eyebrows alone conveying "Told you."

When you had first considered the possibility that Ford would want to examine you as part of his research, it had admittedly flustered you. You'd never even talked to a human prior to them, so the idea of one of them wanting to get into your personal space in such a way was slightly frightening.

Talking to Ford now, though—seeing the earnest, excited curiosity he exuded, hearing the honest awe in his voice—made you far less apprehensive. He wouldn't hurt you, you felt sure of that. In fact, you were almost looking forward to it; it would give you an opportunity to look at them too.

He'd suggested relocating to the nearby island, the morning tide leaving ample, but moderately shallow pools that would be comfortable for you but easily manageable for him.

Which brought you to this; floating on your back in a warm tide pool, both men dressed down to swim trunks and t-shirts, Ford standing in the pool to move around you while Stan sat on the edge, feet dangling in the water.

Ford was very considerate in his examination; asking permission each time he moved on to something new, explaining what he was doing as he went, keeping his touch gentle and noninvasive. He took measurements, vitals, even a swab of tissue from your cheek.

You looked at Stan as Ford pressed a stethoscope to various parts of your body, seemingly amazed by your multiple hearts. Stan gave you a smile and a wink in return, which made a blush rise to your cheeks.

“There’s no need to be nervous,” Ford interrupted the moment to murmur, patting your hand beneficently as he moved the stethoscope again, clearly attributing your uptick in pulse to nerves rather than the embarrassing truth that you were getting flustered by Stan’s flirty look.

 _Was_ he flirting with you? That was a bold assumption to make, but the way his gaze drifted over you when he thought you were no longer looking at him seemed like a pretty strong indicator.

While Ford was looking through some sort of high-tech glasses at your tail fin (studying the blood flow, he claimed), you decided to ask Stan about their encounter with the harpies. He seemed happy to have an audience to tell of their adventure, and you were very keen to hear it.

“...then they started throwing rocks at us, and ain’t talking about little pebbles, no, these were practically boulders. They were trying to herd us, see, get us cornered. Thought they were real clever, trying to pull that trick, but one blast of the sonic gun and they went screeching for cover!”

Ford interjected an explanation of what the sonic gun did; how the high-pitched blasts of sound it emitted would temporarily be painful and disorienting to whoever was on the receiving end of it, but with no lasting damage. Just enough to give them time to escape.

“Then it was just a matter of yanking this dummy—” Stan jerked his chin in Ford’s direction, “—out of there and back to the boat.”

Ford “harumph”ed, but didn’t interject, making you smirk.

“Yes, well,” Ford sighed after a moment, pushing his fancy glasses up onto the top of his head and replacing them with his normal ones, “I’m still disappointed that our encounter with the harpies did not go as smoothly as I’d hoped.”

“The problem is that I wasn’t with you.” Stan smirked. “You’re terrible with the ladies, Sixer. If I was there I could have poured on the old Stan Pines charm. Maybe gotten a free meal out of it, who knows?”

Stan looked at you with a smirk, clearly referencing your help in his fishing endeavors the day before, which made you giggle.

“I highly doubt that,” Ford frowned, looking at his brother with disapproval, which only made you giggle more. “And besides, if I recall _you_ were the one who wanted to stay behind and go fishing.”

“And look what I have to show for it.” Stan indicated to you with his hand. “You got rocks thrown at you, I got to talk to a beautiful mermaid.”

A blush immediately overtook your cheeks, Stan’s open compliment of you sending your hearts even further into a state of elated fluttering. _Beautiful,_ he had called you. Beautiful!

“Yes, well, clearly our friend here is a much more agreeable sort than the harpies. I doubt your presence there would have resulted in anything but the same throwing of rocks.”

“I dunno, Ford,” you murmured, “he seems pretty charming to me.”

“Ha! See!”

Ford gave an exasperated sigh, turning his disapproving look onto you. “Don’t encourage him. His ego is inflated enough.”

“Speak for yourself, Poindexter.”

Ford just shook his head, wading to the edge of the pool to look through his bag of equipment.

“Now, I know this might sound scary,” he addressed you a moment later, “but I assure you it will not be very painful. A mild sort of pinching feeling, that’s all. May I draw a sample of your blood, if you’re comfortable with that?”

“Come on, Sixer,” Stan interjected, his expression slipping into a frown as Ford turned around with a somewhat fancy looking tube with a rather imposing needle on the end. “That’s a bit much, ain’t it?”

“It would be massively useful to me,” Ford said, looking at you instead of his brother. “And I can confidently attest that it really isn’t as bad as you might think, the needle is mildly uncomfortable at the most, and only a fleeting, temporary sensation.”

You chewed the inside of your cheek, admittedly a bit intimidated by the idea of having a needle pierce you, even if it was for science. But you had trusted Ford this far, hadn’t you? If he wanted to hurt you, he easily could have already, ten times over.

“Stanford—”

“It’s okay,” you murmured to Stan, giving him a little, reassuring smile and a nod. “He can take it, I’ll be alright.”

“Thank you,” Ford smiled brightly, moving closer. “Now, it appears that the best place to draw from would be near the bottom of your tail, is that alright?”

You nodded, allowing Ford to draw your fin out of the water, feeling with his fingers for the best place to inject the needle.

Stan suddenly slipping off the edge of the tide pool and into the water surprised both you and Ford, who paused in his search to watch his brother questioningly.

Silently, Stan waded closer to you, reaching out a large hand to take yours, and you let him with a little “oh” of surprise.

“Ford’s a liar,” Stan grunted, squeezing your hand, “that needle stings like a bitch, it ain’t just ‘uncomfortable.’”

“It is not that bad,” Ford protested, earning him a glare from his brother. “ _You_ just have a low pain tolerance. I’m sure our friend here will be perfectly fine.”

“I will clock you, Stanford.”

“When I don’t have a needle in my hand, I invite you to try.” Ford sniffed, returning his attention to your tail, ignoring the annoyed growl in Stan’s throat.

“I’ll give him ‘low pain tolerance’...” he mumbled under his breath, glaring daggers at the other man with a deep frown pulling down the corners of his mouth.

There was a sudden temptation in you to touch his face; to trace the frown on his lips until it lightened, until it was turning back into that playful smirk he seemed to like giving you.

Your blushed again at the fanciful notion, opting instead to sandwich Stan’s hand between both of yours, his huge palm warm and slightly rough.

That brought his gaze back to you, his eyebrows shifting into a pinch of concern that you found deeply endearing.

The needle slipping between your scales at the base of your tail broke the moment, the sting of it making you hiss.

Stan squeezed your hand again reassuringly, bringing his other hand up to stroke gently along the inside of your arm.

“Told you,” he grunted with a shake of his head.

It _did_ sting, he wasn’t joking, but it was manageable.

“Almost done,” Ford murmured, followed by another thirty seconds or so before he finally pulled the needle out, pressing firmly on the injection site with his thumb to stem any bleeding.

“There,” he said with satisfaction. “Wasn’t so bad, was it?”

“It wasn’t the worst thing that’s ever happened to me,” you acknowledged, “but I’d put it a couple steps above ‘mild discomfort,’ you know.”

“Ah, yes, well,” he gave a sheepish smile. “I suppose that’s technically true.”

He released your tail a few moments later, letting it slide back into the water as he turned and waded back to his bag of instruments, two vials of your blood in his hand.

Your hands, however, were still holding one of Stan's, while his other hand continued to gently running along the inside of your arm.

"You finished yet, or what?" Stan asked Ford grumpily over his shoulder.

"Yes, yes, all finished." He closed his bag and turned back to you. "You have been truly wonderful to let me examine you, my dear. I cannot thank you enough."

Ford's compliments made you smile. "For science, right?"

"For science!" He chirped back with a happy laugh. "Now, then—oh."

Ford looked around, his smile slipping away a little bit, prompting you and Stan to take a good look around too, worried that he had spotted some sort of danger.

"Ah, shit," Stan sighed when he realized.

The tide had receded. The tide pool you were in was no longer attached to the ocean, leaving several yards of rocky terrain between you and open water. You were trapped until the tide came back in.

You groaned in frustration, releasing Stan's hand so you could swim to the edge of the pool, looking longingly at the crashing waves out of your reach.

"Oh dear," Ford muttered, stroking his chin thoughtfully. "I'm sorry, I admit I didn't think I would spend so long on the examination."

"Way to go, nerd," Stan said gruffly, folding his arms and giving his brother a glare.

" _Obviously_ it wasn't intentional, Stanley," Ford frowned, mirroring Stan's crossed arms. “And I’m sure we can find a way to get her back to the ocean, as of course I’m not going to expect her just to wait here until the tide comes back in. Maybe I can use some of the tools on board to create a way to attract the water—”

“Overthinking it, as usual, Poindexter,” Stan sighed, climbing back up out of the tide pool. The next thing you knew, he was standing in front of you, extending both hands down for yours.

“Wha…?” you floundered slightly, but he just gave you a crooked grin.

“It’s a short trip, sweetheart, I’ve got you.”

“Stanley—!”

You both ignored Ford, your hands reaching for Stan’s, then he was pulling you up out of the water with shocking strength.

“Up you go,” he murmured, bringing your hands up around his neck. “Got it?”

You nodded, interlacing your fingers behind Stan’s neck as he got his hands under the rest of your body, one hand cradling your back and the other supporting your tail.

Being out of the water was going to get difficult fast, but you'd endure it, especially if it meant being held against Stan's warm body.

You heard Ford following behind you, getting out of the tide pool and gathering up his bag, but you didn't bother to look; too shamefully distracted by seeing Stan's amazing jawline so very up close.

"Jealous of Ford, were you?" you murmured, blushing when he turned his head to look at you. "You had to manhandle me too?"

He barked out a loud laugh, eyes scrunching closed in amusement for a moment. "You don't seem to mind."

You really, _really_ didn't, your blush intensifying as his feet splashed in the shallow water, reaching the ocean and beginning to wade in.

It was a relief to feel the water again, breathing a little easier, tension in your body easing at the familiar territory, though your hearts were still fluttering with excitement at Stan's proximity.

"My hero." You gave him a little smirk, his gaze turning to you as he reached waist-deep. You could have slid out of his arms by then, you were close enough to the water; whether you _wanted_ to, however, was an entirely different story.

"So it's been said." He returned your smirk with one of his own, reaching chest deep in the water, the waves rocking you both, though neither of you had made any effort to let go yet.

"You sure you're okay?" he suddenly asked quietly, his arms squeezing you gently. "Ford didn't make you too uncomfortable, right? Didn't hurt you too much with that needle?"

You shook your head no, and he nodded in acknowledgement. "Good, 'cause I'd beat him up for you if he did."

You smiled with a little chuckle. You somehow doubted he would really do that, but it was sweet of him to say nonetheless.

"Thanks, Stan," you murmured, then before you lost your bravery, you cupped his jaw in your hand; holding him still to press a kiss to his cheek before slipping out of the cradle of his arms to swim away, too nervous to stick around to see his reaction.


	2. Chapter 2

**Summary for the Chapter:**

> All the sexy bits. Mermaid pussy may or may not be inspired by dolphin anatomy, [as studied by Dr Dara Orbach.](https://news.nationalgeographic.com/2017/04/dolphins-genitalia-sex-reproduction-animals/?cjevent=23f82c696e2e11e981d8010b0a24060c&utm_source=4003003&utm_medium=affiliates&utm_campaign=CJ)

You were still thinking about the kiss when your curiosity got the better of you, drawing you back to their boat later that evening. You were blatantly planning on eavesdropping, seeing if they were talking about you, wondering if Ford had actually seen your kiss to Stan's cheek.

What you found instead was Stan having a drink on deck, gazing up at the starry skies.

He sighed deeply, letting his eyes close for a moment, looking so perfectly content all you could do for a long moment was stare.

"Heh," he murmured after a moment, opening his eyes again. "Nothing beats this."

He seemed to be talking to himself, or possibly the star-studded sky, making you smile.

It really was beautiful, the pinpricks of light making a dazzling display overhead, even with the competing moonlight, drawing your eyes up as well for a long look.

"Wondering where you got off to."

Somewhere in the last few moments Stan must have noticed you, stepping up to the railing of the ship to talk.

"Getting examined makes you hungry," you told him, swimming closer to the ship to chat.

He chortled, raising the drink in his hand in agreement. "Yeah, Ford's doing all his nerd stuff with the samples and junk you gave him. I barely got him to break from it long enough to eat something."

He gave a shake of his head an exasperated sigh, but you weren't fooled; anyone could see the deep fondness he had for his brother. Ford being preoccupied elsewhere on the ship, however, might give you a nice opportunity.

"Any chance you want to swim with me?" You bit your lip, sinking down a little, letting the water cover your mouth.

There was clearly no reason to be nervous, though, as Stan’s face positively lit up at the suggestion. “Hell yeah I do, be right in!”

He disappeared from view for a moment, then reappeared without his drink in his hand, replaced instead with the rope ladder. It made a soft _plop!_ as it rolled down the side of the ship and hit the surface of the water, Stan following immediately down after it.

Your hearts were beating double time as you swam over to meet him, the swim trunks and t-shirt he was still wearing from earlier darkening as he entered the water and turned to face you, a broad grin on his face.

“Hi,” he murmured, releasing the ladder to swim slowly away from the side of the boat, his arms stroking, legs kicking.

The water had been too shallow in the tide pools to see either of them actually swim, and it amused you to no end for some reason. He was rather graceless, limbs pushing inefficiently through the water, while your tail propelled you in an easy circle around him.

“Alright, quit showing off,” he huffed with amusement. “We can’t all have fins.”

You giggled in answer, reaching for his hand. “I can help with that.”

“Oh no, not if you’re gonna yank me through the water like a ragdoll.”

Despite the amusing mental image, that was not your intention.

“I promise,” you said solemnly, “I will not yank you around.”

He gave you a scrutinizing look, but closed his hand around yours, seeming to trust your word. You smiled in return, gently pulling him along with you away from the shadow of the Stan O’War II.

“Do you like the stars?” you decided to ask him.

“Not the way Ford does.” He chuckled. “Knowing all the names and stuff. But yeah, I like the stars. Where I grew up, you couldn’t see them very well. Then I moved to a place where you could, and it always amazed me, the reminder of how small we were in the universe, ya know?”

You looked up, and so did he, thinking of all the stars, the worlds, the amazing phenomenon whizzing through the cosmos.

“The ocean makes me feel that way too,” he continued. “There’s so much of it we don’t know about. I mean, clearly, most people don’t think mermaids exist!”

Your people preferred it that way, but you understood his sentiment. There were depths in the ocean even your kind couldn’t explore, harboring secrets of their own and creatures only whispered about.

He looked down, back to you, his hand tightening around yours. “I’d love for you to tell me about it one day. Not just the factual stuff Ford asked you about, but like… your favorite place to find fish back home, or… something. Personal stuff.”

“I’d love to,” you replied eagerly. “Will you tell me about your home? Your family?”

He seemed a little bashful about it, biting his lip, but he nodded. “Yeah… yeah, I can do that. Tit for tat and all that.”

It was your turn to squeeze his hand, smiling at him until a grin spread over his lips again.

“Be honest with me,” he suddenly said, using his grip on your hand to pull you closer to him. “That little kiss earlier wasn’t just a ‘thanks for the ride’ thing, was it?”

You let yourself be pulled, hearts fluttering, until you were right up against him, the moonlight glinting slightly on his glasses.

“No,” you murmured, looking at his lips. “It wasn’t just a thank you.”

The kiss—a proper, on-the-lips kiss, not the mere peck to his cheek that had happened earlier—made you give a soft moan, sliding your arms around his neck.

His mouth tasted sweet, artificially so, and it reminded you that he had been drinking something prior to getting in the water. It was a nice sweetness, whatever it was, but you were looking forward to kissing the taste away, just leaving an unaltered Stan behind.

Then his hands found your waist, fingers tracing the sensitive skin where soft flesh became hard scales, making you moan with a full-body shiver. He moaned in return, pulling you closer, tilting his head to slot your mouths together harder, his eagerness making you feel like you were melting.

The two of you briefly sinking below the surface of the water made him jolt, a kick of his legs bringing you back to the surface.

“Shit, we gotta do this somewhere where I won’t drown,” he groaned, hands sliding up your back.

You could do that.

“Come on,” you murmured, pulling away from him but taking his hand again, guiding you both in the direction of the nearby shore.

The tide was in, making it easy for you both to swim into a tide pool, the shallow water allowing Stan the stability he needed to kiss you absolutely silly without worrying about slipping under the water.

“You’re so gorgeous,” he murmured, a frantic slew of kisses pressed to your mouth, his strong arms curled under your back, his hands cupping the back of your head. “This is the wildest fucking thing I’ve ever done.”

It most certainly was for you too; three days ago you had never even spoken to a human before, but now you were kissing one, and seriously considering getting a lot more intimate than that.

“I want to see you,” you murmured, your hands going to the hem of his shirt. “You humans and your _clothes_ , covering everything.”

He gave a low laugh, helping you peel the wet fabric up over his head without taking his glasses with it, then tossing it to dry land so it wouldn’t get pulled out to sea.

You knew he was hairy, you had seen it from afar on your various peeks at their daily goings-on, Stan unabashed in taking his shirt off under the hot sun. But now you got to _feel_ it, thick and slightly coarse under your hands, all over his chest and abdomen, his arms, his shoulders. You got to feel the soft, pudgy belly he had, though you knew it was deceiving; he had lifted and carried you easily earlier that very day, proof of the dense muscular strength hiding beneath.

“I know I ain’t exactly a prime human specimen or whatever,” his murmured words interrupted your appreciation, your hands pausing on his chest, looking up into his eyes. “But, uh…”

“You’re amazing.” You smiled, your hands sliding up his chest to wrap around his neck. “Just perfect.”

You had a feeling he was blushing; it was hard to tell in the moonlight, but the way his eyes slid half closed, his smile taking on a bashful softness seemed to be strong proof.

“Ah, come on. You’re flattering me.”

“I’m admiring you.” You ducked your head to his chest, feeling the scratch of his chest hair against your lips as you kissed along his collarbones, then lower, down his chest and belly in a gentle trail, the sound of his soft breathing cut off when your head submerged under the water.

You felt his breath shudder as you laid a trail of kisses along his belly and chest, his hands stroking over your head, your shoulders, your shoulder blades. His muscles twitched when you gripped his sides, but he didn’t make you stop.

Breaking the surface of the water again gave you the delightful treat of hearing him give a soft moan, his hands tracing down your arms then back up, gripping them to pull you in.

“My turn,” he murmured gruffly, hands shifting to your back, pulling you up out of the water slightly as his head ducked down, stubble-rough mouth unhesitatingly taking your breast between his lips.

It made you gasp, fingers sinking into his hair, unable to help yourself from curling your tail around him. It surprised and excited you when he rolled with it; one hand reaching down to support your tail as the wide palm of the other hand supported your back to keep you right where his eager mouth wanted you.

Neptune, you were aching. You could feel the thick fabric of his swimming trunks against your opening, the aroused flesh beginning to relax, readying itself to be filled. The realization made you flush even deeper, your face becoming hot as it dawned on you just how much you wanted that.

It was a want that flared hot when he took one of your nipples between his teeth, a gentle pinch and suck sending a jolt of arousal through you that made you gasp. You arched into his mouth, begging him to do it again, and thankfully he seemed happy to oblige.

You didn’t realize that Stan was moving you until your back hit the edge of the tide pool, his body pressing you there so his hands were free to move, free to touch and explore you. He found your waist again—remembering how you’d moaned before when he’d ran his hands along the flesh where skin met scales—and you gave him another one, tilting your head back against the rock, eyes blissfully closed.

“Show me,” he murmured, kissing and licking droplets of salt water from your chest. “Show me where to touch you to make you feel good.”

His demand was like heat spreading through you, making your spine feel as limp as a jellyfish, your breath coming out in dreamy gasps and groans. You couldn’t deny him if you tried, and you really didn’t want to, your hands landing on top of his to guide his touch.

He gasped when you drew his hand to the front of your body, down to where your flesh parted, showing him how to press two thick fingers inside.

“Holy fuck holy fuck holy fuck,” he groaned against your chest, exploring inside you with slow, measured thrusts, angling his fingertips to pet along the slick walls. “Holy… fucking _hell_ the way you _feel_.”

That brought your head out of the clouds a bit, curiosity burning in the back of your head.

“Is it…?” you asked timidly, but Stan was quick to placate your uncertainty.

“It’s fucking _incredible_ ,” he groaned, mouth traveling up your chest to the base of your neck, almost frantic. “You’ve got these… ridges. Humans don’t have that, it’s going to feel _incredible._ ”

You bit your lip as Stan rocked his fingers, the pleasure spot inside you sparking with sensation that made you clench around him with a whimper.

“Oh… _that_ ,” he gasped, raising his head from your neck, clearly watching your face as he did it again; angling his fingers even better this time, giving that spot more pressure, your whole body spasming with how good it felt. “Goddamn I can’t wait to feel that around my cock.”

You gave a sharp whine when Stan added another finger, his thick digits feeling so fucking good you could almost cry, your tail tightening around his legs, your fingernails digging crescent moons into his shoulders. You were going to come, and soon, and you were completely powerless to stop it.

“That’s it,” Stan whispered, rocking his hand, fingertips torturously persistent and firm. “Show me.”

Fuck, yes, _yes_ , he just had to keep doing that; keep his fingers rocking inside you, put his mouth back on your neck or your chest.

"Gorgeous," he murmured with a low, soft groan, his tongue licking a hot stripe up the center of your throat, making you squirm.

It was too intense, you couldn't take it, your fingers definitely leaving bruises on his shoulders as his fingers pushed and pushed until you were there; gasping and arching as pleasure rushed up your spine and burst through your nervous system.

Your heard Stan groan, his head tipping forward against your chest, and for the first time he angled himself just right to press his length against you, grinding against your tail in a desperate seek for pressure.

“Show me,” you gasped at him, hands releasing his shoulders to reach for his waist, trying awkwardly to shove the swim trunks down. “Give it to me, I want to feel you.”

His fingers dug into your waist with a strangled sound, the digits of his other hand slipping from inside you as his head snapped up again.

"Fuck, baby, you're going to be the death of me." Still he helped you push his swim trunks down, freeing the stiff length between his legs with a moan.

Damn you wished the light was better; you were so fascinated with these human bodies, you wanted to see how different he was. He _felt_ different, the skin of his shaft feeling much the same in your hand as the skin on the rest of his body. Such a contrast to a merman's, who would be softer here, slicker.

How rigid and pulsing with eagerness he got was not so different though, nor were the sounds of desire he was moaning against the base of your neck. A simple shift of your body in his arms promised to alleviate that, the thick tip of his cock rubbing against your entrance for a moment before you guided him inside.

You couldn't help your soft cry, your head tilting back against the rock again, one hand on the back of his neck, the other on his waist. The feeling of fullness, the pleasurable pressure on that perfect spot inside you that made sparks fly through your body.

The shaky, breathless moan he gave you as he pulled you in harder, the thrust of his hips that buried him deeper, the clench of his big hands on your tail and your waist—it was all so damn good, all so damn sexy, his obvious pleasure driving you higher.

"God, please, let me—" his hips gave restrained, desperate little hitches, his hand on your tail gripping harder, pushing to manipulate your body as he saw fit. You could think of no reason not to obey the command of his touch, letting him angle you; your tail now between his legs, his knees gripping you on either side, allowing the shift of his cock inside you that was even better than before.

"Stan," you gasped his name, riding the thrust of his hips, your tail curling around his calf, your hands holding him tighter.

"Please tell me this is good," he groaned, lips along your collarbones, hands clenching your waist.

It was such a silly question, such a ridiculous thought when your cunt was spasming in pleasure and your body holding him tight. Of course it was good, how could he think it was anything else?

"Yes," you whimpered anyway, restless hands wandering over him, fingers tangling in his hair, other hand digging into his chest.

"I wanna see you come," you confessed to him, tilting your head up to whisper the words against the shell of his ear. "I wanna feel you come inside me."

His harsh groan filled you with satisfaction, his lips finding yours again even moreso, pleasure swirling inside you and threatening to break at any moment. You could hear the sloppy slosh of the water around you, created by his driving thrusts, a filthy little underscore to the crash of the ocean and the harsh sound of your joint heavy breathing.

Your tail tightened around his calf with a sudden peak of urgency, climax just on the horizon, until the sink of his teeth in your bottom lip served that last bit of pleasurable pain you needed.

A soft cry was all you could manage through your tight chest, climax rolling through you just like the surrounding waves, the hot feeling of his orgasm a few moments later making it all the sweeter.

His fingers were leaving bruises, and you were fairly certain he had dislodged a few scales, but the guttural moan in his throat and the following string of curses was too hot for you to chastise him.

If you had known that your interaction with the small crew of the Stan O’War II could be this good, you wouldn’t have hesitated so long to introduce yourself after finding them.

You just wished you didn’t have to part. That the two of you could sink to the ocean floor together, that maybe before the sun rose you could do this again. Or that you could join him on the ship, see where he slept and lay with him there. Sadly both of those ideas were not compatible with your individual requirements for breathing.

He chuckled a little when he pulled his head back, prompting you to open your eyes and hum a soft, “Hm?”

“I can’t see a damn thing out of these glasses,” he murmured with another little chortle. “The dark’s bad enough, but now they’re all smudged up and wet.”

It made you giggle, uselessly wiping at the glass with your thumbs.

“I’ll clean them when we get back,” he laughed. “I guess I’ll just take it as my due for a good time.”

This time the kiss he pressed to your lips was sweet, soft, making that jellyfish feeling in your back return, as well as the warm, happy heat in your belly.

“Wish we didn’t have to say goodnight,” you sighed, both hands petting over his wet hair and down the back of his neck. “I like this.”

“Heh, me too.”

“Maybe Ford can manufacture you artificial gills.”

He laughed at that, big hands stroking down your sides and tail in a long path. “Maybe. Not sure if he’d approve of what I’d need them for, though.”

“You think?” you murmured, a little nervous at the idea that Ford might not like what they had just done.

“He’d think it was an abuse of science, or something.” Stan chuffed. “He’s a boring nerd who doesn’t think a good lay is something worth dedicating time to.”

“But you do.”

“Fuck, what is life worth living for if not enjoying the good stuff? Food and sex, baby, it’s the simple joys that carry you through.”

“Enough to... do this again?”

His smile was a cheeky mix of amused and boastful, fingers squeezing your waist as he pressed another kiss to your lips. “Honey, as long as you want to tag along with us, I’ll make time for this. I’ve never fucked anyone who felt as good as you. Those ridges... goddamn, I’ve only seen that in sex toys, I had no idea I’d ever feel it for real.”

Even considering all you had just done, it made you blush to hear him compliment something so specific, something unique that you could offer him that made him feel good.

“I think I can manage that.”

**Notes for the Chapter:**

> If you wanna keep up with my wips, check out my [tumblr.](https://guilty-pleasures-abound.tumblr.com)


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